ADVANCES IN THE CULTURE OF THE SILVER POMFRET Pampus argenteus IN KUWAIT Sulaiman M. Almatar and Charles M. James,Kuwait Institute for Scientific Research Aquaculture Fisheries and Oceanography Department P.O. Box 1638, 22017,Salmiya, Kuwait
BACKGROUND Silver Pomfret is most expensive fish in Kuwait and has a world wide market demand and high price. Wild fish stock is on the decline in the northern Gulf due to over-fishing. A five year research project was initiated in April 1998 to assess the technical feasibility of silver pomfret culture in Kuwait. In this talk, a review of the accomplishment of silver pomfret culture will be presented with emphasis on the feeding and growth of fingerlings that obtained last summer.
SOURCE OF EGGS Egg collection and fertilization by stripping fully ripe females and males caught using gillnets. Fully matured males and gravid females occur during May-October at about a depth of 5-20 m in the coastal waters of Kuwait when seawater temperature ranges from 28-31 o C. Fertilized eggs are pelagic of about 1.1 mm diameter. SOURCE OF EGGS cont. Eggs incubated in gently flowing aerated seawater at 29-30 ºC in density of 2000 eggs/l. Egg hatching time is 15 hours at 29.0 30.0ºC. Newly hatched larvae measure about 2.4 mm in total length.
LARVAL REARING Using 1 m 3 and 3m 3 fiberglass round tanks with filtered flowing waters. Optimal temperature for larval rearing is 27-29 ºC. Larval stocking density 30-40 larvae per liter. Significantly high larval survival achieved using mixed algal species consisting Nannochloropsis, Isochrysis and Chlorella compared to that of using single algal species. LARVAL REARING cont.. Larvae fed with enriched Artemia during second week. nauplii Within a week of feeding on Artemia nauplii, the larvae could be weaned to formulated paste feed. Larval survival was up to 4.2% (averaged 3.5%) to juvenile stage (45 days old).
Hatchery performance of silver pomfret from 1998-2004 Year 1998 1999 2000 2001 2002 2003 2004 Total eggs (x10 6 ) 9.28 14.67 7.08 1.38 2.07-2.12 Viable eggs (%) 28.7 37.7 46.1 48.1 27.7-49.2 Egg hatching rate (%) 26.4 20.5 18.5 9.8 10.0-24.0 Hatchery survival (%) * 0.35 0.76 3.5 0.48 <0.1-1.18 No. of fingerlings 1000 4500 7000 200 - - 4000 * 40-50 days after hatching FOOD AND FEEDING OF SILVER POMFRET AT VARIOUS CULTURE STAGES Culture stage Feed regime Period Hatchery Mixed species of microalgae (0.7-1.0 million cells/ml) 0-25 DAH* S-Type Rotifers 2-25 DAH* Artemia nauplii 10-35 DAH* Formulated paste feed 14-45 DAH* Nursery Moist Salmon feed + shrimp meat paste 46-120 DAH* *DAH = Days After Hatching
NURSERY PRODUCTION Rearing using 3 m 3 and 4 m 3 round fiberglass tanks with filtered flowing waters. Paste feed suspended in trays in the water column. For grow-out culture using 4 m 3 to 35 m 3 capacity indoor and out-door culture tanks. General Fingerlings Growth performance observed under tank culture Conditions. Food: Salmon Feed and shrimp meat paste Year 1998 1999 2000 2001 2002 Average 2004 Up to 50 g size Daily weight gain (g/fish) 0.34 0.1 0.25 0.20 0.04 0.35 0.62 SGR (% day) 0.91 0.7 0.52 0.41 0.62 0.56 4.80 Above 50 g size Daily weight gain (g/fish) - - - 0.23 0.02 0.21 1.32 SGR (% day) - - - 0.29 0.15 0.20 2.13 Indicating high potential of increasing growth of fingerlings and Juveniles silver pomfret
Comparison between shrimp meat VS Salmon feed shows significantly higher growth using shrimp meat alone. Salmon feed (41.4% protein) Shrimp meat (50.2% protein) % % Salmon feed 90 Shrimp meat 90 Krill 3 Krill 3 Aquastim F* 1 Aquastim F* 1 Minerals 0.5 Minerals 0.5 Gut conditioner 0.2 Gut conditioner 0.2 Vitamin C 0.05 Vitamin C 0.05 Multi-vitamins 0.25 Multi-vitamins 0.25 Fish oil 5 Fish oil 5 * INVE, Belgium Growth in relation to using shrimp meat alone vs. Salmon feed 65 60 Weight (g) 55 50 45 40 shrimp meat Salmon feed 35 30 25 1 14 28 Duration (days) Shrimp feed: grew from 29.13 to 59.98g (daily weight gain 1.14g fish -1 d -1 ) Moist Salmon feed from: 28.22 to 44.2g (0.58g fish -1 d -1 )
To further investigate the growth performance of fingerlings two feeds were used: 1. Cyclopeeze + formulated feed (34% protein). 2. Shrimp meat +formulated feed (44.5% protein). Using 1m 3 fiberglass tank with 3 replicates (M 60 fish per tank), duration: 28 days. FEED COMPOSITION Cyclopeeze + Formulated feed Shrimp meat + Formulated feed % % Cyclopeeze* 45 Shrimp meat 45 Salmon feed 45 Salmon feed 45 Krill 3 Krill 3 Aquastim F** 1 Aquastim F** 1 Minerals 0.5 Minerals 0.5 Gut conditioner 0.2 Gut conditioner 0.2 Vitamin C 0.05 Vitamin C 0.05 Multi-vitamins 0.25 Multi-vitamins 0.25 Fish oil 5 Fish oil 5 * ARGENT Lab., USA ** INVE, Belgium
Growth in relation to adding Cyclopeeze vs Shrimp meat in the diet 20 16 cyclopeeze+formulated feed shrimp meat+formulated feed Weight (g) 12 8 4 0 1 14 28 Duration (days) Cyclopeeze: grew from 4.17 to 18.47 g (average daily weight gain 0.51 g fish-1day-1) Shrimp meat: grew from 4.47 to 21.37g (average 0.60 gram fish -1day-1) Conclusion: - High potential for increase of growth rate of fingerlings and Juveniles of silver pomfret. - High protein requirement.
BROODSTOCK DEVELOPMENT Sexual differentiation for the male and female are completed at the ages of 115 and 135 days old after hatching from the egg. 4 m 3 to 30 m 3 capacity indoor and out-door tanks used. Gonad maturation evidenced by occurrence of fully ripe 134g size male producing milt and first occurrence of female with stage-2 gonad at 222.5 g size till 2003 culture period. During 2004, a 408 g size female with stage-iv ovary observed but the tank was infested with Cryptocarion that hampered the spawning attempt. ACKNOWLEDGMENTS The following people have contributed to the production of larvae and juveniles of silver pomfret used in this study: Drs. K. Al-Abdul Elah, E. Cruz, K. Lone, S. Al- Ablani, and R. Fernandez, Mr. T. Abu-Rezq, Mr. A. Al-Marzouq, and Mr. H. Al-Gharabally.